Hodgkin, Sir Alan Lloyd (1914-1998), was an English medical researcher who provided a detailed explanation of the transmission of nerve impulses. Hodgkin did most of his research in collaboration with Andrew F. Huxley of England. The two scientists shared the 1963 Nobel Prize in physiology or medicine with Sir John C. Eccles, an Australian scientist who also worked on nerve transmission.
Hodgkin and Huxley showed that the transmission of a nerve impulse is an electrical and chemical process controlled by the outer membrane of the nerve cell. The membrane selectively allows ions (electrically charged atoms) of potassium and sodium, which carry a positive charge, to enter and leave the cell. When the cell is at rest, potassium ions move easily through the membrane, but sodium ions do not. The protein molecules inside the cell have a negative charge. As a result, the interior of a resting nerve cell has a negative charge, but an accumulation of sodium ions outside the cell membrane creates a positive charge there. A stimulus applied to the cell causes the membrane’s pores to open and allow positively charged sodium ions to rush into the cell, reversing its charge. This sudden change of electrical charge makes up a nerve impulse. When the impulse has passed, potassium ions flow to the outside and the cell quickly returns to its normal negative charge.
Hodgkin was born in Banbury, England, on Feb. 5, 1914. He studied natural sciences at Trinity College, part of Cambridge University. From 1939 to 1945, during World War II, he designed radar systems for aircraft. Hodgkin returned to Cambridge after the war and spent almost his entire career there, becoming a professor in 1952. He was knighted in 1972. From 1970 to 1975, he served as president of the Royal Society, one of the world’s foremost scientific organizations. He was master of Trinity College from 1978 to 1984. He wrote an autobiography, Chance and Design: Reminiscences of Science in Peace and War (1992). Hodgkin died on Dec. 20, 1998.
